2015 Crop Season Wind-down—or Wind-up?

November is usually the last month of the year with significant field activity. Crops have been harvested, fall tillage is getting done where soil type and topography is suitable, and most stored manure – liquid or stacked – has been field-applied. While doing fall fieldwork you should keep your eyes open since it may have implications for crop management in 2016.

How was your weed control?

How was your weed control, particularly in corn but also in other forage crops? If it was good, congratulations – but don’t rest on your laurels. That’s because even small weed escapes can result in a significant problem next year because of the thousands of seeds a single plant of many weed species produces. If the escapes were due to spray skips, then the same herbicide program may control the weeds next year. However, if the weeds were truly resistant to the herbicide(s) used this year, using the same products in 2016 probably won’t work any better – and the situation will probably be worse. Even if your weed control was almost perfect, you might want to consider rotating to another product or tank mix in 2016. You rotate crop species, and you should also rotate herbicide programs. Fortunately, new and oft-better herbicides continue to reach the marketplace, so there are plenty of options available.

Do you have your crops custom-applied? If so, review your weed control situation with your custom applicator, especially if control was less than ideal, but even if it was pretty good. Often, you may be spraying your fields before weed problems occur, especially with pre-emergence applications, and unless you contact your sprayer, they probably assume that whatever they applied did the job. These folks are often knowledgeable about the latest herbicides and know what’s working well – and what isn’t. A good custom applicator can be a valuable part of your “crop team.” When I was managing the crop operation at Miner Institute, one of the few areas where I didn’t take the lead was in herbicide selection. We had a competent applicator who kept up on the latest products, including what was working best for his clientele. (Miner Institute still uses this applicator – why argue with success?) We made sure he knew which fields we were going to seed to alfalfa the following year since that can greatly impact herbicide choice, but other than that we let him make most of the weed control decisions.

Keeping and using crop records

We often emphasize the need to keep good crop records, but less often we discuss how to use them. Most farmers keep some sort of planting record, even if it’s only a note about when each field was planted. But harvest records are also important, and yields can be either determined or estimated depending on whether the farm has drive-over scales.

An increasing number of moderate-to-large farms have installed drive-over scales near the silo area, making yield determination relatively simple. However, if you don’t have scales, at least keep track of the number of truckloads or self-unloading wagons of forage harvested from each field. My experience after having reviewed literally thousands of scale weights is that the weight of truckloads of chopped corn is fairly consistent, especially when converted to a dry weight. You may be able to get an idea of the yield of your corn crop by a “tractor seat” appraisal – not numerical yield per acre, but a good-fair-poor estimate. However, this isn’t nearly as simple with perennial forage crops due in part to multiple harvests per season. That’s why some sort of quantitative estimate is needed to intelligently decide whether a particular field is productive enough to maintain for another year or if it should be rotated to another crop – often corn, but there are other options.

Using whatever yield data you have, drive over these fields with a critical eye: Has an alfalfa-grass field petered out, now having turned to mostly grass? If so, and if you plan on keeping this field in hay production, plan on ordering enough nitrogen fertilizer to topdress the field early next spring. The higher percent grass, the more nitrogen needed for economical yields. If yields were low and there’s not enough grass for nitrogen to significantly boost yields, the field is a good candidate for crop rotation.

Photo courtesy: doomu/istock

Now is prime time for soil sampling

You’ve probably read it before in this column, but I much prefer fall as the time for soil sampling. No month on livestock farms is an “easy” month but some months are better than others, and this usually includes November. Taking soil samples before the ground freezes will provide more reliable results, especially if sampling is done about the same time of the year (not necessarily November, but late summer or fall versus early spring, for instance.) I’m particularly cautious about making potash fertilizer recommendations based on early spring soil samples because the freeze-thaw cycle can temporarily result in unreliable soil test data.

Another recommendation you’ve read here before: Use the same soil test lab each year since the various labs may use different soil extractants. One extractant isn’t necessarily superior to another, but they provide wildly different numbers that make year-to-year comparisons almost impossible. One of the big advantages of doing a conscientious job of soil sampling (a soil analysis is only as good as the sample on which it was based) and then using the same lab year after year is that you can see the effect of your soil fertility program on your fields under your crop management. This can provide more useful information than even the most capable soil fertility expert or agronomist – even me! At Miner Institute we used this type of information to increase our potassium fertilizer applications on alfalfa-grass fields above the soil test lab’s recommendations, with a resulting positive impact on yield. And note that I said “soil fertility program,” not “fertilizer program;” that’s because, especially on livestock farms, a substantial portion of crop nutrients come from manure applications.

About the AuthorEverett Thomas

Ev Thomas has worked as an agronomist in New York for 45 years, first with Cornell University Cooperative Extension, then with the William H Miner Agricultural Research Institute in Chazy, N.Y. including managing its 680-acre crop operation. He continues to work part-time for Miner Institute and is now an agronomist at Oak Point Agronomics. He has written our Forages column for 16 years and has been an expert contributor on a number of projects.